The oblique muscles on both sides of your abdomen help control several movements of your lumbar spine, or your lower back. When you're doing your abs routine, don't forget to perform exercises that strengthen your obliques, whether you're working out in a gym or your back yard.

Crunches

The basic crunch is among the best-known exercises to tone up your abs. It targets the rectus abdominis in front of your abdomen, but also works your obliques. Lie on your back with your knees bent, your feet flat on the exercise surface and your hands behind your head. Lift your head and shoulders, but keep your lower back on the ground. You’ll also find an almost limitless number of crunch variations. The most effective crunch variation for strengthening your obliques -- according to a 2001 American Council on Exercise study -- is the bicycle crunch. Assume the standard crunch position, but extend your legs and lift them to about a 45-degree angle to the ground. Perform the exercise by raising your left knee toward your chest while simultaneously lifting your head and shoulders and twisting your torso to the left and trying to touch your knee with your right elbow. Repeat the motion on the other side, trying to touch your right knee with your left elbow.

Planks

Planks are isometric exercises that target your abs but also engage a variety of leg, hip and upper-body muscles as stabilizers. Perform a standard plank by positioning yourself face down on your exercise surface. Balance on your toes and forearms and position your elbows under your shoulders. Begin the exercise by straightening your body, from the top of your head to the soles of your feet, then hold your position for 30 to 60 seconds. As with the crunch, you can choose from many plank variations. For example, you can target your obliques directly by doing a side plank. Begin by lying on your left side with your right leg stacked on top of the left. Prop up your torso by leaning on your left elbow and forearm, then lift your body toward the ceiling, leaving just your left arm and the side of your left foot on the floor. Your body should be straight and aligned from head to toe. Hold the plank position for 30 to 60 seconds.

Leg Raises

Find a horizontal high bar -- at the gym or outdoors at a park -- and do hanging leg raises, which work your obliques as assisting muscles. Grasp the bar with your arms extended, palms facing forward and your feet off the ground, then bring your knees up to your chest. Make the exercise more intense by holding a weight between your ankles or a medicine ball between your knees.

Considerations

Warm up before you begin your abs routine by doing 5 to 10 minutes of light aerobic exercise, such as jogging in place or walking. Follow with several minutes of dynamic stretches, such as side bends, trunk rotations or diagonal knee chops to loosen up your obliques. The knee chop stretch is similar to a standing bicycle crunch, but you stand up and keep your back straight throughout the activity. Raise your left knee to about mid-chest level and touch the knee with your right elbow. Lower your leg, then lift your right knee and touch it with your left elbow. Consult your doctor before starting any new exercise routine, especially if you’ve been less active of late or you have health issues. Stop performing any exercise if it causes you pain.

About the Author

M.L. Rose has worked as a print and online journalist for more than 20 years. He has contributed to a variety of national and local publications, specializing in sports writing. Rose holds a B.A. in communications.